Automatic control device for elevators



(No Model.) 3 Sheets-Sheet 1.

E. G. MERRILL & B. J. FOLEY. AUTOMATIC CONTROL DEVICE FOR ELEVATORS.

No. 595,326. Patented Dec. 14, 1897.

HUB 12 (No Model.)

3 Sheets-Sheet 2. E. O. MERRILL & B. J. FOLEY. AUTOMATIC CONTROL DEVICE FOR ELEVATORS.

Patepted Dec. 14, 1897 I n van Z-o rs.

Sunbeam 7 3 Sheets-Sheet 3.

(No Model.)

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UNITED STATES PATENT OFFICE.

EDWIN O. MERRILL AND BARTHOLOMEIV J. FOLEY, OF PITTSBURG, PENNSYLVANIA.

AUTOMATIC CONTROL DEVICE FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 595,326, dated December 14, 1897.

Application filed. August 22, 1896. Serial No. 603,623. (No model.)

To aZZ whom it may concern:

Beit known that we,E1)W1N O. MERRILL and BARTHOLOMEW J. FOLEY, of Pittsburg,Pennsylvania, have invented a new and useful Improvement in Automatic Control Devices for Elevators, which improvement is fully set forth in the following-specification.

This invention relates to automatic control devices for elevators; and its first object is to provide means for locking the elevator when any door of the elevator-shaft is opened, so that the elevator cannot move from the floor at which a door has been opened until the latter has been closed. A reliable and simple device for this purpose has been greatly desired as a safeguard against accident, and the legislature of one of the States has required that all elevators be equipped with mechanism for this purpose.

This part of' our invention consists in a pneumatic control system or a system operated by compressed air, the object being to insure certainty of action by means of simple mechanism. According to ourinvention each elevator-door is provided with connections whereby when a door is opened a valve in the compressed-air system is actuated, causing application of the locking mechanism. The locking mechanism and the connections whereby it is actuated may be of many different forms; but it is preferred to apply the stopping device or look to the elevator-controller.

The invention also has for its object to provide mechanism operated by compressed air whereby the operator can on approaching a floor, by the manipulation of a lever or other device, cause the door of that floor to open. The opening of the door causes the locking of the elevator, as already explained. To start the elevator, the operator first moves the lever to close the door, after which the ele vator being released may proceed on its way. The exhaust air from the door operating mechanism is utilized to operate the locking mechanism.

The whole system can be most conveniently explained in connection with the accompanying drawings, in which we have illustrated the application of the system to one of the of the valve.

well-known types of elevators in common use. It will, however, be understood that the mechanism or some parts thereof must be modified for application to elevators of a different type.

In the drawings, Figure 1 is a front elevation looking toward one of the doors and the elevator-car. Fig. 2 is a side elevation. Fig. 3 is a section of one of the door-controlling valves and its casing transverse to the axis Fig. i is a section at right angles to Fig. 3. Fig. 5 is an end elevation of the valve and its actuating mechanism. Fig. 6 is a sectional detail of one of the lock-controlling valves. Fig. 7 is a sect-ion, partly in elevation, of the governor-wheel and the looking mechanism. Fig. 8 is a sectional elevation on line 8, Fig. 7; and Fig. 9 is a sectional plan of part of the door-operating mechanism.

We have shown the mechanism for one floor only of the building, and it will be understood that each floor will be equipped with mechanism similar to that shown.

In the drawings, A represents an elevatorcage, and B a door on one of the floors.

The mechanism for starting, stopping, and reversing the elevator is of ordinary construction and will require but a brief description.

O is the operating-lever in the car. It may occupy any one of three positions. In that indicated in Fig. 2 the car is supposed to be moving downward. This lever controls a shifting beam 0, having on each end a roller 0. The guide-rope c is looped around each of these rollers and at its lower end passes around the controller-wheel D. The latter is on a shaft D, which has at one end a crank arm or tappet d, which is connected with the valve of the hydraulic elevator mechanism in the usual way. This mechanism forms no part of the invention and therefore is not illustrated. It suffices to state that in one extreme position of tappet cl the elevator is moving upward, in the other it is moving downward, and in the intermediate position it is brought to rest. The bearing of shaft D carries in the rear of wheel D an upright abutment E, and wheel D has on its rear side two stop-screws e e, which by contact with abutment E limit the movement of the wheel I). As seen in Fig. 2, the wheel D is in one of its extreme positions, screw 6' being in contact with abutment E.

F represents the lockingpiece, pivoted at f to a supporting-frame F and hollowed out so that it can embrace the abutment E when thrown into its locking position. Then in that position, (shown in Fig. 8,) it is in the path of the stops 6 e, and so prevents the movement of the wheel. It will be observed that locking-piece F can only be thrown into its operative position when wheel D is in its intermediate position-that is to say, when the car is at rest. Now the result to be accomplished by this part of the mechanism is to throw the look into action by the opening of the door B. When the apparatus is constructed as shown in the drawings, this is accomplished in the following way: A suitable tank or reservoir 10 contains air at a moderate or low pressure. One pound above atmospheric pressure has been found sufficient. Suitable means for supplying air to reservoir 10 and regulating the pressure therein are provided, as will be presently shown. From reservoir 10 is led a discharge-pipe 12, which passes up the elevator-shaft and is open to the atmosphere at its upper end. Adjacent to each door B is a valve 13, which is normally open. Consequently under normal conditions-that is, when all the doors are closed-there is a current of air passing through pipe 12 and escaping at its end. Valves 13 are all controlled by the doors B, the valve being held open when the door is fully closed and closed when the door is opened. The valve-actuating mechanism is shown in Fig. 6. The stem g of the valve 13 projects through and beyond the stunting-box g, and its outer end is in contact with an arm G, pivoted at G, and having at its lower end a roller G lVhen door B is closed, the side of the door-frame presses on roller G and tilts arm G sufficiently to lift valve 13 off its seat against the pressure of spring g As soon as door B moves in the direction to open it spring g closes valve 13, as shown in Fig. 6. Consequently the pressure accumulates in pipe 12, and this will occur whenever any door of the system is opened. From pipe 12 a branch pipe 1% leads to a casing I'I, containing a flexible diaphragm h, which actuates the lock F. As shown in Fig. 7, the parts are in their normal position. Lock F is connected by a link f 3 with a lever f,which amplifies the movement of diaphragm h, to which it is connected by a link f As soon as the air being cut off by the closing of one of the lock-control valves 13 accumulates behind diaphragm h the latter is forced outward, setting the lock and holding it in that position until the control-valve is opened, which does not occur until the door is fully closed.

It will be readily seen that the principle embodied in the mechanism just described of causing compressed air controlled by the movement of a door to lock and unlock the hoisting mechanism may be carried out in many different ways.

M represents the main air-supply pipe. As shown in Fig. 1, a branch pipe 15 connects the main with reservoir 10. In this branch are a stop-cock 7t and a pressure-reducing valve 7a. This branch is used for filling the reservoir initially and to maintain the pressure therein in case of deficiency in the normal source of supply, which, as will presently be shown, is the exhaust -air from the dooroperating cylinders. A safety or blow-off valve on is provided to prevent excess of pressure in tank 10, and pipe 12 has aleak-valve m set to permit the desired amount of air to pass.

\Ve will now describe the mechanism for automatically opening and closing the doors. Above each door and supported from the ceiling or otherwise is a cylinder N, in which is a double-cupped piston N. The projecting end of piston-rod n is secured to the crossbar of a rectangular frame I, the side bars of which embrace the cylinder N, and which is reciprocated by piston-rod a. To the end of frame P, opposite the piston-rod, is jointed by pivots p a yoke g, which is at one end of a lever G}, which is pivoted at Q. At its end (1 lever Q is jointed to link Q which in turn is pivoted to door B. The latteris suspended, as usual, by rollers I) from rail B. Obviously, through the connections just described, the movements of piston N will be transmitted to the door to open and close the same. It is also obvious that various mechanical connections may be substituted for those described. In the position of the parts shown in Fig. 1 the door B is closed. Piston N is controlled by a valve S, there being, of course, one valve for each door. For convenience these valves will be termed the door-control valves. Figs. 1 and 2 indicate the positions of these valves and the connections of the piping, and Figs. 3, i, and 5 illustratein detail the valve and its actuating devices. The main air-pipe M has abranch 16 to each valve. The pressure in this pipe must be high relatively to that in the tank 10 and its connected pipes. IVe have found that a pressure of fifteen pounds above atmospheric pressure gives good results. From valve S two pipes 17 and 18 lead, respectively, to opposite ends of cylinder N. hen main M is connected with pipe 17, the pressure will be exerted on piston N on the side to close the door, and when connected with pipe 18 the piston will be reversed and the door opened. A fourth pipe 19 leads from valve S to tank 10. This is the exhaust-pipe, so that the exhaust-air from cylinders N goes to supply the low-pressure reservoir.

In Fig. l the relation of the valve to the different ports it controls is shown, and to facilitate understanding of the operation IIO the several air-passages in the valve casing are designated each by the numeral of the pipe with which it connects. Passage 16 connects with the branch to main M, passage 17 leads to the door-closing side of piston l while groove 3 connects the other pipe with the exhaust-port 19. In the position shown in Fig. 4 the inlet 16 is connected with the door-closing end of cylinder N, while the other end is in connection with the exhaust. A slight turn of valve S on its axis will reverse these connections and cause the door to open. It will be observed that by the operation of the valve S not only is the door opened and closed, butit is locked in each of these positions until the valve is shifted.

The valve-shifting mechanism may be variously constructed. As shown, the valvespindle has a crank-arm T, connected by a pin T with a bar T arranged to slide in grooves between two parts V V of the valvecasing. These parts are fastened together by screw-bolts t, by means of which wear may be taken up. On its projecting end bar T carries a roller 15 This roller occupies such a position that it may be acted upon by a shoe WV, carried by the elevator-car and under 0011- trol of the operator therein.

Y represents the operating-handle, Fig. 2, in the form of a bell-crank lever. Its short arm is jointed at y to a link y, pivoted to a fixed support at if. Lever Y is jointed at g to the stem w of shoe WV, and its short arm forms with link y a toggle. In the normal position (shown in Fig. 2) shoe W will just clear roller 75 on passing it. IVhen the operator wishes to open a door, he throws lever Y to the right, moving shoe WV into the path of roller 6 Bar T will consequently be moved to the position shown in Fig. 5, shifting valve S and opening the door. Lever C having been brought to its central position to stop the car, look F is automatically applied, preventing further movement of the car until the door is closed. To accomplish this, lever Y is moved back to its first position, whereupon spring S restores valve S and the door is closed by the air-pressure.

Every time this operation is performed the exhaust-air from cylinder N passes to reservoir 10.

Manifestly the apparatus for automatically lockin g the elevator and that for opening and closing the doors could each be used independently of the other; but to accomplish the full object of the invention the system as a whole must be used.

Having thus described our invention, what we claim as new, and desire to secure by Letters Patent, is

1. The combination of the controller-wheel carrying two stops, an abutment cooperating with said stops to limit the movement of the wheel, a locking-piece movable between said stops when the wheel is in a central position, and pneumatic actuating mechanism for said locking-piece operated by the opening of a door in the elevator-shaft, substantially as described.

2. In an elevator system, the combination with a door of the elevator-shaft, and with a lock for the hoisting mechanism, of devices actuated by compressed air for opening and closing the door, means for operating said devices from the car, and mechanism, operated by the exhaust-air from door-operating devices, for actuating said lock, the lock-actuating mechanism being controlled by the position of the door, substantially as described.

3. In an elevator system, the combination with an elevator-door, of a lock for the hoisting mechanism, pneumatic mechanism for operating said look, a low-pressure tank and piping for supplying air to said mechanism, a lock-control valve operated by the door, pneumatic mechanism for opening and closing the door, comprising a cylinder, a piston connected with the door, and a door-controlling valve, a supply-pipe leading to the valve, an exhaust-pipe leading from said valve to said low-pressure tank, and means for regulating the pressure in said tank, substantially as described.

I11 testimony whereof we have signed this I specification in the presence of two subscribing witnesses.

EDXVIN C. MERRILL. BARTHOLOMEW J. FOLEY.

Witnesses:

WM. K. GRAY, WM. 0. CHARLTON. 

